docs: def ccor2(alt, r, h1, zh, h2):
      '''
  /*        CHEMISTRY/DISSOCIATION CORRECTION FOR MSIS MODELS
   *         ALT - altitude
   *         R - target ratio
   *         H1 - transition scale length
   *         ZH - altitude of 1/2 R
   *         H2 - transition scale length #2 ?
   */
   '''
      e1 = (alt - zh) / h1;
      e2 = (alt - zh) / h2;
      if ((e1 > 70.0) or (e2 > 70)): # pragma: no cover
          return 1.0 # exp(0)
      if ((e1 < -70) and (e2 < -70)): # pragma: no cover
          return exp(r)
      ex1 = exp(e1);
      ex2 = exp(e2);
      ccor2v = r / (1.0 + 0.5 * (ex1 + ex2));
      return exp(ccor2v);